<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    /* conic-gradient() 角向渐变 */
    .demo {
      width: 100px;
      height: 100px;
      margin: 0 auto;
      background: conic-gradient(red, yellow, lime, aqua, blue, fuchsia, red);
    }
  </style>
</head>
<body>
  <div class="demo">

  </div>
</body>
</html>